Drill



Nov. 1, 1938.

G. J. BARRETT ET AL DRILL Filed May 10, 193'! Patented Nov. 1, 1938PATENT" OFFICE.

DRILL George J. Barrett and Sosthene Robichaux,

Houston, Tex

Application May 10, 1937, Serial No. 141,589

6 Claims.

This invention relates to a drill and has particular relation to thattype of .drill to be used in drilling wells through rock or. other hardformation.

It is an object of the invention to provide a drill having a pluralityof side cutters for disintegrating the formation at the outside of thebore as the drill progresses and having suitable cross-rollers at thelower end of the drill for disintegrating the material at the bottom ofthe bore.

In a preferred embodiment of the invention more than two side cuttersare provided, there being preferably four. side'cutters as shown. Themajor portion of the work is performed'by the rolling side cutters andthey are subjected construction for mounting the cross-rolling cuttersfor disintegrating the central portion of the bore.

It is another object of the invention to provide a drill of thecharacter described that is of simple construction and which may bereadily assembled or dismembered for repairs and replacements.

With the above and other objects in view the invention has particularrelation to certain novel ing member.

usual passageway 3 downwardly therethrough' Figure 4 shows afragmentary, sectional view of another embodiment.

Referring now more particularly to the drawing wherein like numerals ofreference designate the same parts in each of the figures, the numerall' designates the drill head which is upwardly'extended and formed withthe shank 2 for connection to the drill stem or other driv- The shankand head have the for the discharge 'of the drilling fluid. The

- lower end of the head isformed with the spin- .dle anchors 4,1 and 5,5, which arespac'ed'apart aroundthe lower end of the head and whoseinnersides present the flat bearing faces 6, 6 and l, 1, which divergedownwardly.

Converging inwardly and downwardly from the anchors 4, 4 are thespindles 8, 8 and converging inwardly and downwardly from the anchors,5, 5, are similar spindles .9, 9.

The

outer ends of these spindles, in assembly, may

be fitted through bores as It! through the corresponding anchors 4, 5,and then welded in place, as more clearly shown in Figure l.

Frusto-conical shaped rollers II, II are rotatably mounted on thespindles 8 and frustoconical shaped rollers l2, H are rotatably mountedon the spindles 9. In a preferredem=- bodiment of the invention therolling cutters II are oppositely disposed and the rolling cutters l2are also oppositely disposed as more clearly shown in Figure 3. Thesecutters are provided with external cutting teeth which roll about theouter portion of the bottom of the bore, and disintegrate the hardmaterial encountered.

There is a bridge l3 whose upper end is circu- I lar and concaved, saidupper end being fitted into a correspondingly shaped countersunk groovel4 around the lower end of the passageway 3 and preferably'welded inplace. This bridge has the depending legs l5, l6 which are spaced apartand which have transversely aligned bearings to receive the spindle I'I.One end of this spindle may be an enlarged head l8, if desired, and theends of the spindle are arranged adjacent, but are not connected to, theopposing faces l9, l9, into which the inner ends of the spindles 8 areformed.

Mounted on the spindle ll between the legs l5, [6 there is a rollingcutter 20. This rolling cutter,'as shown, is approximatelyfrusto-conical shape in form with its smaller end located.

left between the cutters 20 and 22 and the cutter 22 is so located thatit will disintegrate that portion of theformation left between thecutter 2| and the cutters l2.

It will be noted that the cutters 12 are extended inwardly further thanthe cutters II, the arrangement being such that the cross-rollingcutters 20, 2|, 22 will traverse the entire area at the bottom of thebore not disintegrated by the side cutters I i, I2.

Since the major portion of the work of the drill will be performed bythe side cutters II and I2, a greater number of said side cutters havebeen provided than is now commonly used so that each side cutter will besubjected to less wear than would otherwise be the case and the fulldiameter of the bore will thus be maintained. In the embodiment shown inFigure 4 the bridge B21 is provided with only the depending leg IS inwhich the spindle IT has a bearing and in this form said spindle I! mayhave one end, or both ends if necessary, welded to the adjacent spindle,or spindles, 8. The bridges l3, l3a are provided with suitable ducts as23 whereby the flushing fluid may be delivered onto the respectivecutters.

If desired, the leg may be laterally braced by means of the braces 24which are welded thereto and to the inner end of the spindles 9 as moreclearly shown in Figure 3.

As indicated in Figure 1 the side rolling cutters H, l2 are mounted torotate on anti-friction *rollers 25 and ball bearings 26.

In assembly the cutters may be slipped over 7 this process. The racewaysin which the balls 26 ride will then be in registration and these ballsmay be inserted into their raceways through suitable gates, left in thespindles for that purpose and the gates then plugged up by welding inthe usual manner. The spindles may then be inserted through the bores l0and welded therein and the bridge with the cross-rollers assembledthereon may be welded into place and the drill thus completed. P

It may be found most practical to make the bores l0 in-the form of slotsextending down to the ends of the anchors 4, 5 inrwhich case the rollingcutters ll assembled on their spindles 8 and the bridge [3 with thecross-rolling cutters mounted in place thereon may be inserted as a unitinto place, the outer ends of the spindles 8 passing up into saidslot-like bores l0 and these parts may then'be permanently welded inposition and the side cutters l2 assembled on their spindles 9 may thenbe inserted into the position shown in Figure 2 and the spindles 9welded in place' and thereafter the braces 24 may be formed on the headand arranged to disintegrate the formation at the bottom of a well boreand some extending inwardly further than the others and rolling cutterson the drill mounted to'rotate on a transverse axis and arranged todisintegrate the formation at the centralportion of the bore. 1

3. A drill comprising ahead, four downwardly and inwardly convergingspindles thereon, outside frusto-conical rolling cutters on saidspindles arranged to disintegrate the formation at the outer portion ofthe bore, each of said cutters being of a unitary structure and someextending inwardly further than the others, a leg anchored to the headand depending therefrom, means connecting said leg to some of saidspindles, a

transverse rolling cutter support on the leg whose 1 ends are adjacentother of said spindles andcross-rolling cutters on said support arrangedto disintegrate the formation at the central portion of the bore.

4. A drill comprising a head, four outside rolling cutters mounted to,rotate on the head and arranged to disintegrate the formation at thebottom of the, well bore, each cutter being of a unitary structure andtwo oppositely disposed of said cutters extending inwardly toward theaxis of the drill further than the other of said cutters and rollingcutters on the drill mounted to rotate on a transverse axis and arrangedto disintegrate the formation left at the central portion of the bore bysaid outside cutters.

5. A drill comprising a head, four spindle anchors depending from thehead and spaced apart approximately a uniform distance around the head,downwardly converging spindles on the anchors, frusto-conical shapedcutters mounted to rotate on said spindles, each cutter being of'aunitary structure and two opposing cutters extending inwardly furthertoward the axis of the head thanrthe other two cutters.

6. A drill comprising a head, a transverse spindle at the lower end ofthe head, rolling cutting means on the spindle arranged to disintegratethe formation at the central portion of the bore, four outsidefrusto-conical rolling cutters on the head spaced apart in approximatelyuniform distance around the head, two opposing rolling cutters extendinginwardly toward the center of the head further than the other two ofsaid roll ing cutters.

GEORGE J. BARRETI. SOS'I'HENE ROBICHAUX.

